Bleach: Thousand-Year Blood War is the final story arc for the Bleach anime, being a visual reboot of the series while pushing the story into wild, unexplored territory. The final arc brings back many old faces while also introducing many new villains, all of whom hail from the Wandenreich, or the Quincy empire. The Sternritter, or elite Quincy, use weapons that not even Uryu Ishida could imagine.
For years, Uryu was the poster boy of the Quincy tribe, proudly stating that his tribe uses bows and arrows instead of zanpakuto to fight Hollows. His father Ryuken and his grandfather Soken followed that trend, but the Sternritter use more than bows. They also have bankai-stealing medallions and even swords, acting more like Soul Reapers than Uryu ever did, proving that the Quincy tribe isn't what Uryu thought it was.
Why the Wandenreich Contradicts Uryu's Understanding of Quincy
At first, the Wandenreich's use of swords seems like a retcon in light of what Uryu once said about Quincy weaponry. The Ishidas all used bows, and Uryu insisted that Quincy used those weapons exclusively in the past, only for several Sternritter and even King Yhwach himself to use swords in battle. These are not zanpakuto but ordinary spirit swords that cut the enemy and little more, so there are no Quincy shikai or bankai aside from any bankai stolen with the medallions. Instead, characters like Bambietta Basterbine and the ruthless Quilge Opie use swords as backup weapons in case their bows or other powers can't finish off the enemy. The reason for all this is a practical one: the Quincy can't afford to hold back.
The Quincy faced a genocidal war centuries ago, and the survivors fled to their hidden empire, the Wandenreich. They spent many years preparing for revenge, and they knew that their next war, come victory or defeat, would be their last. So, Yhwach and his Sternritter made sure to use every possible advantage because if they held back and lost, they wouldn't get another chance. Thus, the Quincy innovated new weapons and tricks, from their bankai-stealing medallions and their wealth of data to their odd but effective use of swords.
Now, Quincy like Bambietta have plenty of weapons, from bows and Schrift to basic swords, and it helps that a sword can block a zanpakuto but a bow cannot. Bambietta only held off Sajin Komamura's blade because she had one of her own, and she might have been in trouble otherwise. Even King Yhwach used an energy sword to fight and finish off Yamamoto when a bow might not have sufficed. The Quincy are fighting not for glory or principle but rugged survival. They won't compromise themselves by being too proud to use weapons similar to the Soul Reapers' own. Uryu might be too proud for that, but he's not the one fighting for long-overdue revenge or survival.
Why Wandenreich's New Weapons & Techniques Weren't Known to Uryu
Even if the Wandenreich's members have practical reasons to use off-brand weapons like swords against the Soul Reapers, surely Uryu, a proud Quincy himself, would have seen this coming and not explained the bows-only rule to Ichigo. Most likely, Uryu simply didn't know about all this, meaning the Wandenreich's medallions and swords will likewise take him by surprise. Uryu is out of the loop with his Quincy tribe, as recent Bleach episodes showed -- he didn't even know about this war or the reason why the Soul Reapers sought to destroy the Quincy tribe. For all his pride as a Quincy, Uryu knows very little, though it's not his fault. He was never invited to join the Wandenreich no matter his faith in the Quincy tribe.
Uryu is a human Quincy, which puts him in the minority. He and the other Ishidas are mortal human beings with spiritual gifts, living relatively ordinary lives in the world of the living. Meanwhile, the pure-blooded Quincy, or Echt Quincy, kept to themselves in the Wandenreich as the strongest and most capable Quincy. There, they gathered intel on the Soul Reapers and developed new weapons like swords and medallions in secrecy, evidently never sharing any of this with the half-blood Quincy living on Earth.
Perhaps it was too risky for the Sternritter to approach the Ishidas and other half-bloods, as Soul Reapers might then become privy to this and take action. Alternatively, the half-bloods were deemed unworthy to join the Wandenreich and were simply left to their own devices. Only pure-bloods like the Sternritter are trusted with the Wandenreich's best weapons to get revenge for all Quincy-kind, and it's Uryu's job to just stand back and watch. This isn't his fight -- it's Yhwach's.